A thermoplastic elastomer composition having superior balance between the gas-barrier property and flexibility, comprising a specific thermoplastic resin matrix in which a specific rubber elastomer ingredient is dispersed as a discontinuous phase is known. See Japanese Unexamined Patent Publication No. 8-259741.
Further, it is also known that, by having a melt viscosity (ηm) of the thermoplastic resin ingredient and a melt viscosity (ηd) of a rubber elastomer ingredient in the thermoplastic elastomer composition satisfy a specific relationship, a high elastomer ingredient ratio is achieved and thereby a thermoplastic elastomer composition having more flexibility and a superior gas-barrier property is obtained. There is also known a pneumatic tire using this thermoplastic elastomer composition as a gas-barrier layer. See Japanese Unexamined Patent Publication No. 10-25375.
Further, there is also known a thermoplastic elastomer composition comprising a thermoplastic elastomer having a thermoplastic resin as a matrix and a rubber composition as a dispersed phase in which a barrier resin composition having a phase structure dispersed in a flat shape is introduced so that the gas-barrier property is greatly improved and the flexibility, oil resistance, cold resistance and heat resistance are provided to the thermoplastic elastomer composition. See Japanese Unexamined Patent Publication No. 10-114840.
Further, there is also known a thermoplastic elastomer composition comprising an aliphatic polyamide resin modified by a layered silicate into which an acid anhydride-modified ethylene-based modifying polymer is blended. See Japanese Unexamined Patent Publication No. 2000-160024.